Recently dug up 5 Pieris japonica completely covered with lace bugs also 2 deciduous fragrant azaleas growing along side of them also infested. I live in Chemainus BC, every Pieris that I come across as I’m out walking is also infested. Nurseries here have some for sale that are showing signs also. What should I do (organically) to treat soil where they were growing .Torch soil, boiling water have been suggested. Help
Lacebugs do not live in the soil so treating the soil would be a waste of time. You did the best thing possible by digging them up and hopefully disposing of them off your property. Lacebugs overwinter as eggs in plant foliage and produce 4 to 5 generations per year after hatching in May. Pieris japonica growing in sunny locations is much more vulnerable to attack than it is in shade while Pieris floribunda (Mountain Pieris) and Pieris formosa (Himalayan Pieris) are resistant, even in sun. If you have other azaleas and/or rhododendrons in your garden, keep a close eye on them for lacebug activity. They are very hard to get rid of once established.
